Helicopter



S. HILLER, JR

Sept. 13, 1949.

HELICOPTER Filed Feb. 21, 1944 6 Sheets-Sheet 1 I lNVENTO R.,'. STANLEY H/LLER JR. M 777% ATTORNEY.

P 1949- s. HILLER, JR 2,481,745

HELICOPTER Filed Feb. 21, 1944 6 Sheets-Sheet 2 INVENTOR, STANLEY H/LLER JR.

BYM7WW ATTORNEY p 1949- s. HILLER, JR 2,481,745

HELICOPTER Filed Feb. 21, 1944 6 sheetsesheet 5 0 /o3 Y H q 1-" T v I 2:. 55

INVENTORT STANLEY H/LLER JR.

A 7' TO/PNE K Sept. 13, 1949.

'S. HILLER, JR

HELICOPTER Filed Feb. 21, 1944 f4 V //l 72,

6 Sheets-Sheet 4 ATTORNE).

Patented Sept. is, 1949 UNITED STATES PATENT orrica HELICOPTER Stanley Billet, Jr., Berkeley, Calif., assignor, by mesne assignments, to United Helicopters, Inc" Palo Alto, Calif., a corporation of California ApplicationFebruary 21, 1944, Serial No. 523,181 6 Claims. (Cl. 170-13524) This invention relates to the structure and controls of helicopters which, as is well known, are actuated by horizontally rotating wings and do not require a minimum forward speed to attain buoyancy or steering control.

A helicopter having a single set of wings, or more sets rotating in the same direction, will rotate about the axis of the wings du to the torque resulting from driving them, in the absence of means to avoid such counter-rotation. This diiiiculty has been avoided in practice by having a projecting part such as a tail, on the helicopter, with an air propeller thereon to exert aforce to compensate for the torque. This has resulted in consumption of power which in no way adds to the buoyancy or speed of the helicopter, and it has been considered a necessary loss. In helicopters having wings rotating in one direction only, those moving forwardly on one side of the helicopter in the direction of movement of the helicopter will have greater speed with respect to the air than wings moving backwardly or rearwardly on the other side thereof, and the wings will thus have a greater bite on the air when moving in such forward direction than when moving in such rearward direction. This has resulted in undesired effects on the helicopter. To decrease such effects, it has been customary to pivot the rotating wings so that they could rise or fall angularly about the pivot points in planes including theiraxes of rotation; and stop members have been provided to limit the pivoting, generally to an angle of about thirty-five degrees (35). The

wings flapped automatically, due to their changing bites, rising at one side of the helicopter and falling at the opposite side thereof, centrifugal force tending to throw them out toward the horizontal, this imparting the lift to the body. Such flapping action of. the wings made it impossible to have closely adjacent, oppositely rotating, coaxial wings because they would collide with each other when they flapped. I

Objects of my invention are to avoid useless torque effects; to cause torque in the correct amount in the correct direction for the correct period of time to turn or orient the craft; to provide means to cause the wings which rotate substantially horizontally to have varying effects on the air as they rotate; to control and make use of the different effects for moving the craft forward, backward, to either side, up, down, or in any desired combination of directions, either with or without turning it; to provide means which will afford universal controls of the craft; to provide means to afford such universal controls Without changing the speed of rotation of the wings, if so desired; to make the actuating means for all of the controls easily available to the operator; to provide a helicopter having closely adjacent oppositely rotatable coaxial wings which are not tiltable with respect to their axis of rotation, which axis is fixed with respect to the-body of the helicopter; to provide a helicopter having wings rotatable at constant speed, whileaflording universal and easy control; and other objects will be app rent after reading this specification.

Wings rotating in opposite directions about a common axis neutralize the torque effects of each other if balanced, and the forces exerted by them are then used solely forcausing buoyancy and/or the intended motion of the helicopter. The wings have a certain sheet on the air to exert force thereon, and such eflect is herein termed bite. The bite of a rotating or in fact any blade or wing on the air is a. function of the tilt or pitch thereof, the speed thereof with respect to the air, the shape thereof, and possibly of other factors as well. Increasing such speed, or decreasing it as for example by means of a brake on the rotating shaft thereof, or otherwise, or change of pitch or shape of the wing, or possibly changes in other factors, will change the degree of bite. with the bite of each of the oppositely rotating wings increasing gradually to a maximumat the same point in the cycle of rotation and'decreasing to a minimum at a point one hundred and eighty degrees opposite that point, the whole helicopter will be lifted more at the point of maximum bite and less at the point of minimum bite. The force exerted will then tendto move the helicopter obliquely away from the earth. Such force has a horizontal component. and a vertical component, the horizontal component being in a direction from the points of maximum to minimum bites. The helicopter will move in a horizontal direction if the force. exerted thereon by gravity just neutralizes the vertical component; and it will move obliquely up or down if the force of gravity is less than or more than the vertical component, respectively. The obliqueness of the path of the helicopter and its speedin that path can be controlled by controlling the total pull of the rotating wings and the tilting effect thereof, and these may in turn be controlled by adjusting the sum of the total maximum bites of the rotating wings and the amount of change of the bites during rotation. By changing the point of maximum bite to another location on the circle of rotation of the wings, the helicopter can be made to move in a direcl the parts in different of the control column; 1

3 t I 'tion having a diii'erent horizontal component, in any direction that may be chosen. Thus, the helicopter can be made to move in any desired horizontal direction, in any desired oblique direction, vertically up or down, or held stationary at any point in the air.

It will thus be apparent that the helicopter can be heldstationary at any point or moved in.

' any chosen direction in three dimensions, at any accomplished in any suitable manner by any suitable means. it being preferred to do so by adjustment of the bites of the oppositely rotating wings. It is now apparent that full control of the bites of .each set of oppositely rotating wings as described above, will result in complete and universal control of the helicopter while it isupright or substantially so. Control of the bites may be had in various ways, as by controlled change of speed of rotation of the individual sets of oppositely rotating wings, by controlled bending of the wings or otherwise changon the seat l4.

opposite directions, it

controls of the pitches of the upper and lower blades are actuated by means located convenient-. ly and within easy reach of the pilot while sitting As seen on Figs. 1 and 9, such actuating means on a control post 24 in turn mounted on a pivot 25 to tilt forwardly or rearwardly, a hand operated lever 25 mounted on a pivot 21, and afoot operated lever 28 mounted on a pivot 29. The upper and lower setsv of wings are rotatable in beingimmaterial which rotates clockwise. Merely by way of example, the upper set is shown as rotatable clockwise when looking down.

A drive shaft 32 (Figs. 1 and 7) is driven by the engine IS, with a clutch 33 interposed to permit running the engine without rotating the ing the shape thereof by means of ailerons thereon or otherwise, or by controlled adjustments of the tilt or pitch of the rotating wings, and there may be other ways and means of controllably adjusting the bites. Forpractical p poses,- I prefer change of pitch. a l

The preferred exempliflcation of the invention is illustrated .on the accompanyingv drawings forming a part of this specification, on which Fig. 1 is a right-hand side elevation of my helicopter;

Fig. 2 is, a top plan view thereof'with parts broken away;

Fig.3 is a top plan view with parts broken away;

Fig. 4 is a side elevation of the pitch control the hollow shaft wings when desired. On the drive shaft 32 is a bevel gear34 which meshes with upper and lower gears 35, 36 respectively. The shaft 32 rotates in ball or other suitable bearings 31. The gear 35 is attached to a hollow shaft 38 which is within the column or casing i8, and the gear 36 is attached to a hollow shaft 42 which is within 38. The gears 35 and 36 are in ball bearings 43. The hollow shafts 38 and 42 are thus rotated in opposite directions by the drive shaft. A rod 44 is within the hollow shaft 42, the lower end of which is threaded threaded bolt 45 having a'flange 46 fastens the bolt 45 to a sleeve 41. end of such sleeve is within and splined to the hollow shaft 42 at the lower end thereof. The sleeve and consequently the rod 44 thus rotate mounted to rotate 4541. A nut with and are movable longitudinally of the hollow shafts 38 and 42. -A stop member such as a flange 48 strikes against the lower end of the shaft 42 and limits the upward movement of the rod with respect to such shaft, the uppermost position being shown on Fig. 7. Means are pro- I vided to move the rod longitudinally with respect mechanism-,partly in section, and with the near wings removed, and is a section on the line 4-4 on Fig. 6; 1

Fig. 5 is a view similar to that of Fig.4 with position;

Fig. 6 is a vertical section of the upper part Fig. 7 is a vertical the control col Fig. -8 is a horizontal on Fig. 4; and r Fig. 9 is a diagrammatic view of the controls.

My helicopter, as seen on Fig. 1, comprises a body ,with more or less conventional landing gear I2 thereon. Any type of landing gear, for landing on the ground, on a roof, or on the water, may be used. A door I3 is provided to permit of entrance to and exit from the seat 14, and another door I5 is preferred togive access to the engine 16, which, through suitable gearing within the gear casing l1, drives two concentric hollow shafts partly within the hollow column or casing l8 which forms an extension of the gear casing. Such shafts, through suitable gearing, drive, one the upper set of rotating blades l3, Na, and the other the lower set of rotating blades 20, 20min opposite directions. Various section of the lower part of section on the line 8-8 hereinafter.

Similar hollow arms 54,

"6) which can be'tilted in is rotatably mounted on to the hollow shafts, which will be referred to Similar hollow arms 43, 58 (Fig. 6) are fixedly mounted on the hollow shaft 42 to rotate there with. Mounted for rotation within the hollow arms, by means of ball bearings 5|, are hollow shafts 52, 53 respectively. The wing I9 is mounted on the hollow shaft 53, and the wing l9a is mounted on the hollow shaft "52. The pitch of these wings, that is, the angleat which they bite into the air, is changed and controlled by rotation of the hollow shafts 52, 53 on their axes. '55 are fixedly mounted on the hollow shaft 38, within which are hollow shafts 58, 51 respectively, similar to the shafts 52 and 53 and similarly mounted. The wing 20 of the shafts 56 and51 on their axes. The shafts 52 and 53 will Be rotated oppositely to each other to increase, or decrease, the pitch of both wings i9 and Ho, as the case may be, since such wings face in opposite directions. Likewise the shafts 56 and 51 will be rotated in opposite directions to increase the pitch of both wings'28 and 20a, or to decrease the pitch of both, since these wings also face in opposite directions.

I provide means to cause of pitch of the wings through a range, as they rotate. This comprises any direction and raised or lowered. -A ring 62 comprise a wheel 23 mounted within a flanged hollow interiorly The upper continuous change I a wobble plate 6| (Fig.f

-' -ball bearings 88 about the periphery of the wobble plate, this ring, together with certain connections for the pitch controls which are attached thereto, rotating with the .lower wings 20, 20a. The wobble plate 8| is mounted on a support 84 having a spherical bearing surface 84a, as does the wobble plate, which permits tilting in any direction.

Attached to the ring 82 by diametrically opposite ball and socket or other hinge-like connections 85 and 88, are upwardly projecting links 81 and 88. Extending crosswise of and obliquely from the shafts 58, 81 through slots as at 13 (Fig. 4) in the hollow arms 54 and 55, are bent arms 1|, 12, the ends of which are pivotally attached to the links 81, 88 respectively. Also pivotally attached to the links 81, 88 are upwardly extending links 18, 18. Bent arms 11, 18 are fixedly connected to another wobble plate 8| and pivotally to the links 15, 18. The wobble plate 8| cannot wobble freely in any direction as can the wobble plate 8|, but only about the axis defined by the pivot pins 82 on the ring 83 splined to the hollow shaft 88 so that it can move longitudinally thereof and rotate therewith; the axis of pivot pins 82 being perpendicular to the plane of linkage 81, 18, 11 and 88, 18, 18.

A ring 84 is mounted for rotation about the periphery of the wobble plate 8| by means, for

example, of ball bearings 85. Pivotally attached to the ring 84 at points ninety degrees (90) from the pivot pins 82, by ball and socket connections 88, 81, are upwardly extending links 88, 89.

The rod 44 has an enlarged circular portion 82 to center it within the hollow shaft 42. Attached to the upper end of the rod 44 and adjustable thereon by means of screw threads 83, is a cap 94 splined to the hollow shaft 42 to be rotatable and movable longitudinally therewithin. A flange nut 55 on the cap portion limits the downward movement of the rod 44 by striking against the upper end of the hollow shaft 42, the upward movement being limited by the flange 45a, as previously described. A pivot member 88 is attached to the cap, and bell crank levers IOI, I02 are mounted at the angular portions thereof upon the pivot, member 98. These bell crank proper raising or lowering of the rod 44 to tilt levers have arms I03, I04 extending outwardly in opposite directions away from the pivot member 88, and also arms I05, I08 extending downwardly at opposite sides of the hollow shaft 42. The links 88, 89 are pivotally connected to the arms I03, I04. Pivotally connected to thedownwardly extending arms I05, I08 of the bell crank levers IOI, I02, are downwardly extendingoblique links I01, I08 which in turn are pivotally connected to bent arms III, ||2 which extend through slots as 3 (Figs. 4 and 5) in the hollow arms 49, 50, and they are connected to the hollow shafts 52, 53.

The rod 44 thus provides an axially movable anchor for the linkage connected to the shafts 52 and 58- on which the upper wings are mounted; and such rod is raised by rotating a lever 4 (Figs. 1, 4 and '7) in one direction and lowered by rotating such lever in'the reverse direction. It is attached as by bolts or screws I I5 to an annular member I I8 rotatable on a ball bearing I I1. The outer face of the annular member II8 has coarse threads which register with similar threads on the inner face of the casing member II8, the registering threads being shown at H9. These threads are coarse so that rotation of the lever 4 through even a slight angle will cause the fixed to the shaft wings as will be referred to hereinafter.

The wobble plate 8| is raised or lowered in a somewhat similar manner, but by two independ-- ent levers I2 I I 22. The support 84 for the wobble plate 8| has a downward extension I28, the outer face of which has coarse screw threads registering with similar threads on the inner face of the upper part of an annular member I24, the threads being shown at I28. The lower part of the member I24 has coarse screw theads on its outer face which register with similar threads on the inner face of an annular member I28, the threads being shown at I21. The member I28 is maintained at constant level with respect to the casing I8, for which purpose it is provided with an inwardly projecting flange I28 which, with the lever I22, forms a groove in which is a flange I28'on the casing II. The lever I2I is attached to the annular member I24 by bolts I8I; and the lever I22 is similarly attached to the member I28 by bolts I82. Thus, rotation of either of the levers I2 I I22 will raise or lower the support 84 for the wobble plate 8| and this wobble plate itself axially of the casing I8.

The inner face of the upper end of the casing I8 forms a bearing surface for the hollow shaft 38, and the outer face of such casing forms a surface along which the member 84 can slide on rotation of either of the levers I2I or I22. Attached to and depending from the hollow arms 48 and is an annular member I33 to form a bearing surface for the hollow shaft 38.

The upper wings I8, |8a rotate with the inner hollow shaft 42, and the lower wings 20, 20a with the outer hollow shaft 38, the shafts and wings thereon rotating in opposite directions. The ring 84 rotates about the upper wobble plate 8|, A along with the links 88, 89, the bell crank levers IOI, I02 and parts appurtenant thereto, and the upper wings I8, I9a. The. wobble plate 8| itself rotates in the opposite direction with the hollow shaft 38 and the lower wings 20, 20a, as do the ring 82 on the lower wobble plate and the links 88, 15 and appurtenant parts.

Arms I85, I38, I31, I38 (Fig. 9) are attached to the wobble plate 8| at ninety degrees apart. A flexible cable I40 is connected at its ends to the arms I38 and I38, and intermediate its ends it passes over pulleys MI and over a pulley I43, and it is wound around a drum I44 I45 of the control wheel 23. The center of rotation of the pulley I43 is at the axis of the pivot 25. Turning the wheel 23 will cause tipping of the wobble plate 6| in the direction of the arms I38 or I38, the direction of tipping depending on which way the wheel 23 is turned. A flexible cable I48 passes over a pulley I41, and it is connected to the arm I31 and to the control post 24 at the point I48. A flexible cable I5I passes over a pulley I52, and it is connected to the arm I35 and to the control post 24 at the point I53. The control post is mounted to tilt about the pivot 25, forwardly away from, or rearwardly toward, the pilots seat, that is to the right or left respectively as seen on Fig. 9. Tilting the post 24 forwardly pulls on the cable I48 which. pulls on the arm I31 to tilt the left side of the wobble plate 8| downwardly. The right side of the wobble plate 8| is thus tilted upwardly to cause the arm I35 to pull on the cable I5| to take up the slack in the cable I5I' caused by the forward tilting of the control post. Tilting the control post rearwardly causes the right side of the wobble plate 8| to tilt downwardly and the whole operation is the reverse of that due to tilting the control post forwardly. The points I48 and I53 of attachment of the cables I46 and lil are on opposite sides of the pivot 25 and are so chosen that a pull on either of such cables will take up the slack caused thereby in the other. The wobble plate I can be tilted in any desired direction and to the desired degree by properly coordinating the rotation of the wheel 23 and the tilting of the post 24.

The levers III, III and I22 are rotated by;the hand operated lever 28 and the foot operated lever 2|, as shown diagrammatically at the lower part of Fig. 9. The levers H4 and I2I are rotated in unison by the hand lever 26, and with this in view they are shown. as connected together fixed relation to each by a rod I54 to which a, 111::-

I55 is connected by pivot means I56, such link being connected to the hand lever by pivot means I 51. Operation of the hand lever causes the levers H4 and I2I to rotate together, in either direction as desired. The lever I22 is connected to a cable I58 passing about a pulley I59, the ends of the cable being attached to the foot lever 28'at opposite sides of the pivot 29 thereof. Movement of the foot lever does not cause appreciable slack in the cable 458, and forward movement of the left side of such lever causes the lever I22 to rotate rearwardly, while opposite movement of the foot lever causes the lever I22 to rotate forwardly.

The pitch of both the upper and'lower wings varies continuously and gradually through. a range at all times that the helicopter is flying in a direction having a horizontal component, and such range of change of pitch becomes zero and the pitch of both the upper and lower wings remains constant when the pull of the wings is merely straight up. The direction of tilt of the lower wobble plate GI controls the wobbling of the upper wobble plate BI and determines the point, which is the same in each revolution, at which both the upper and lower wings have the greatest pitch and the point in each revolution in which they have the least pitch. Either of these points can be chosen at will anywhere in the path of rotation, the other point being one hundred and eighty degrees (180) therefrom. The helicopter as a unit travels in a horizontal direction which is the same as that from the" point of greatest to the point of least pitch. Raising the lower wobble plate 6| raises the upper wobble plate 8| (and vice versa) and increases the pitch of the upper wings and decreases the pitch of the lower wings, while lowering the wobble plate will do just the reverse. This causes a change in the torque eil'ect and the turning of the body of the helicopter to orient it. Raising the rod 44 decreases the pitch of the upper wings without affecting the pitch of the lower wings; and lowering the rod 44 increases the pitch thereof, also without affecting the pitch of the lower wings. The effect on the pitch of the upper wings of raising the rod 44 is made equal to about twice that of the effect thereon of raising the wobble plate, so that when both the wobble plate and the rod are raised or lowered together, there is a simultaneous and equal decrease or increase in the pitches 'of both the upper and lower wings. Hence, rod 44 serves copter move sidewise to the left without turning the body, and the wheel 24 is rotated to the right to make the helicopter move off sidewis'e to the right without turning the body. Proper coordination of the wheel" and the post 24 will make the helicopter move in any desired horizontaldirection. The left end of the foot lever '28 is pushed forwardly to rotate the body of the helicopter to the left about the vertical axis of the rotating wings, and the right end of such foot lever is pushed forwardly to cause the helicopter to rotate similarly to the right. The hand lever 26 is pulled untoward the seat to increase the exerts .apull on that end of i to the arm. I"

the lower wobble plate down. This causes the as an altitude or collective pitch control member;

turned to the left, that is. counterclockwise look ing at it from the pilot seat, toomake the heliplate 6| in a direction altitude of the helicopter, and it is pushed down away from such seat to decrease its altitude, it, of course, being understood thatthere is a point in the position of the hand lever intermediate be-' tween ascent and descent at which the helicopter canbe maintained at constant level or even sta-.- tionary in the air. I

Pushing forwardly on the wheel 23 to tilt the control post 24 forwardly exerts a pull on the cable I48, which, in turn, pulls the lower end of the arm- I 31 towards the pulley I41, and thereby tilts the lower wobble plate 6| to the left of the pilot sitting in his seat as seen on Fig. 9. The ring 62 thus rotates in an oblique path and thereby causes the upper wobble plate 8| to wobble as thewings rotate. With the parts in the positions shown on Fig. 9 and at each quarter rotation therefrom, the tilt of the lower wobble plate does not result in tilting the upper wobble plate, but in the positions ninety degrees therefrom, the upper wobble plate is at maximum tilt. There is a continuous gradual increase of tilt of the upper wobble plate from the points of minimum to maximum tilt thereof, and there is a continuous gradual decrease of tilt of such wobble plate from the points of maximum to minimum tilt thereof. such continuous tilting of the upper wobble plate, due

to the previously described connections thereof to the rotating wings, causes the pitch of both wings to decrease gradually and continuously as they move forwardly with respect to the direction of travel of the helicopter, and to increase gradually and continuously wardly thereof. Thus, for example, with the greatest pitch of the blades, directly at the rear of the helicopter, the helicopter tilts and moves forwardly.

Pulling on the wheel 23 to tilt the control post 24- rearwardly exerts a pull on the cable I5I, and thereby pulls the lower end of the arm I35 toward thepulley I52 to tilt the lower wobble that just described, namely, toward the right of the pilot with the parts in the positions,

shown on Fig. 9. imum tilt of the the helicopter which and flies backwardly.

Turning the wheel 22 to the left, that is, counterclockwise as seen by the This places the point of maxthe cable attach and pulls the rearmost end of upper wobble plate to wobble in such a inan ner thatthe pitches of the wings decrease gradually and continuously as they move to theleft, and increase gradually and continuously as they right side of the left side, the left'side as they move rearwhich is the reverse of blades at the forward part of is thereby tilted rearwardly pilot from his seat.

thereof and thereby moves sidewise to the left andwithoutturnlngthebody.

Turning the wheel 23 in the opposite direction, that is, to the; right and clockwise as seen by the pilot from his seat, will cause the point of greatest pitch of side of the helicopter. This-causes the left side of the helicopter to rise higher than the right side thereof. It tilts toward the right side and moves ofl in that direction. It will be apparent that by coordinating the direction and amount of turning of the wheel 23 with the direction and amount of tilting of the post 24, the point of greatest pitch can be placed in any direction from the axis of rotation, and the helicopter can be caused to move horizontally in any direction without turning the body.

When the pilot with his feet on both ends of the foot lever 28 pushes the left end thereof forwardly away from the seat, there is a pull on the cable I 56 which causes the lever I22 to rotate rearwardly, that is, counterclockwise looking down. This rotation of the lever I22, due to the intermeshing of the threads I21, causes the support for the lower wobble plate to rise. This causes the upper wobble plate to rise .an equal amount since they rise or descend together, and

this results in the upper wings having an increased pitch and the lower wings a decreased pitch. The bites of the upper and lower wings will be unequal and the bite of the upper wings will be the greater, thus causing a torque efiect which causes the body H to rotate about the center of rotation-of the wings in a direction opposite to that of the rotation of the upper wings. Pushing forward on the left end of the foot lever 26 thus causes the body to rotate to the left about the axis of rotation of the wings.

Pushing the right end of the foot lever 28 forwardly causes the wobble plates to descend and in turn the upper wings assume a decreased pitch and the lower wings an increased pitch. This causes a torque efiect which causes the body to rotate about the center of rotation of the wings in a direction opposite to that of the rotation of the lower wings. Pushing forward on the right end of the foot lever 28 thus causes the body to rotate to the right about the axis of rotation of the wings. a

It is preferable to have the changes in pitch of the upper and lower wings, for the purpose of rotating the body in either direction, balance each other so that the combined pulling or lifting power of both sets of wings will not be substantially changed. This permits of body rotation by a single control means without change of altitude, no matter whether the helicopter is moving horizontally or is stationary.

The handle of the lever 26 is pulled toward the pilot's seat to make the helicopter rnove upwardly axially of the center of rotation of the wings; and such lever is pushed forwardly away from such seat to make the helicopter descend axially of such center. Pulling such lever causes the levers Ill and l2l to rotate counterclockise as seen looking down on the helicopter. Such rotation of i the lever l2l lowers the wobble plates, which increases the pitch of the lower wings and tends to decrease the pitch of the upper wings. Such rotation of the lever Ill raises the rod 44, which increases the pitch of the upper wings through its connections thereto, and overcomes the tendency toward decreased pitch of the upperwings due to lowering of the wobble plates. The

the wings to be at the left increase in pitch of the upper wings due to the lever ill should preferably'be justgreat enough to make the actual increase in pitch of the upper blades substantially'equal to the increase in pitch of the lower blades due to the lever l2l, so that a torque differential will not be setup and the helicopter can me without rotation of the body. In other words, the increase in pull of the upper blades due to the lever Ill should equal to the increase in pull of the lower blades due to the lever Hi, and an additional amount equal to the loss of pull of the upper blades due to the lever I2 i With the pulls of both the upper and lower blades increased the same amount, no torque effects are thereby produced and the total pull is increased which causes the helicopter to ascend.

When the handle of the lever 26 is pushed forwardly away from the seat to cause the helicopter to descend axially of the wings, the levers I i4 and i2! are rotated clockwise. Such rotation of the lever l2i causes the wobble plates to rise and this causes the pitch of the lower wings to decrease and the pitch of the upper wings to increase. Such rotationof the lever I I4 causes the rod 44 to be lower and this causes the pitch of the upper blades to decrease. The total decrease in pull of both the upper and lower blades is the same leaving them so thattheir torques neutralize each other. Descent along the line of the axis of rotation of the blade is therefore without undesired rotation of the body.

This invention affords the pilot control of twodimensional horizontal movement of the helicopter by proper setting of the wheel 23 about its axis and proper setting of the post 24 about its pivot or axis. Control of movement in a third dimension is afforded by proper setting of the hand lever 26. Control of rotation of the bodyis afforded by proper setting of the foot lever 28. The pilot can keep both hands on the wheel 23 when change of altitude is not desired-and he needs to remove only one hand therefrom to actuate the hand lever 26 for change in altitude. One hand can thus always hold the wheel 23. A

- grasp on the wheel 23 is sumcient to rotate such wheel in either direction, to tilt the post 24 in either direction or to hold either or both steady. Universal control of the helicopter is made pos-v sible and easy by the present invention, by properly coordinatin the various controls, so long as the helicopter remains right side up. It would, of course, be possible during change of altitude by means of the hand lever 26 to have the oppositely rotating wings ordinarily produce unequal torque effects of which the algebraic sum would result in rotation of the body which might be controlled and overcome by use of the foot lever 28.

During operation, the lower wings bite into air that is moving downwardly because it has been forced downwardly bythe upper wings, while the upper wings bite into fresh airthat is. unaffected As a result, the lower wings reby any wings. quire a greater pitch than the upper wings for both wings to have the same degree of bite, and produce equal and opposite torque effects on the body. A fixed adjustment of the relative wing pitches can be made to offset thisldifi'lculty, orit 'sible. Difierentways of tatable about its axis,

11 a distribution thereon, by use of the control wheel 23 and/or control post II. at least to a degree.

Other variations of the invention are also posare possible. The specific methods heretofore'described are the simplest and are preferred although many variations, including those referred was well as others, fall within the broad scope and spirit of the invention.

I claim:

1. A helicopter comprising a hollow shaft roa wing, means supporting said wing for rotation with said shaft and for adjustment as to pitch; wobble mechanism adjustable axially along said shaft, means for effecting said axial adjustment of said wobble mechanism, a rod within said shaft adjustable axially with respect thereto, means for effecting said axial adjustment of said rod, and linkage connecting the wobble mechanism and the wing to adjust the pitch of said wing in one direction upon axial adjustment of alone, said linkage including a lever member pivotally connected to said rod whereby when said rod and said wobble mechanism are both simultaneously axially adjusted the pitch of said wing is adjusted in an opposite direction.

2. A helicopter comprising an outer hollo shaft andan inner hollow shaft within the outer shaft and projecting beyond an end thereof, said shafts being rotatable in opposite directions about a common axis; a wing secured to the projecting portion of the inner shaft for rotation therewith and pitch adjustment thereon; a second wing; secured to the outer shaft for rotation therewith and pitch adjustment thereon; wobble mechacoordinating the controls said wobble mechanism nism between said wings axially adjustable along i said axis including a collar connected to the outer shaft for axial movement along said shaft and rotation therewith, an inner ring tiltably supported by said collar. and an outer ring joumalled on the inner ring; additional wobble mechanism below said second wing axially adjustable along said axis including a tiltable inner ring, and an outer ring journalled on such inner ring; linkage interconnecting the inner ring of the first mentioned wobble mechanism, the outer ring of the additional wobble mechanism, and the second wing; linkage anchoring means including a rod within said inner hollow shaft and which is axially adjustable along said axis; and linkage anchored on said rod and interconnecting the first mentioned wing and the outer ring of the first mentioned wobble mechanism. I

3. A helicopter comprising an outer hollow shaft and an inner hollow shaft within the outer shaft ,and projecting beyond an end thereof, said shafts 'being rotatable in opposite directions about a common axis; a wing secured to the projecting portion of the inner shaft for rotation therewith and pitch adjustment thereon; a second wing secured to the outer shaft for rotation therewith and pitch adjustment thereon; wobble mechanism between and an outer ring" such inner ring; linkage intercong 12 M 1 v a tional wobble mechanism, and the second wing: linkage anchoring means including a rod within said inner hollow shaft and which is axially adjustable along said'axis;

taneous axial adjustment 4. A helicopter comprising an outer hollow and projecting beyond anend thereof, said shafts being rotatable in opposite directions about and pitch adjustment thereon; a second wing secured to the outer shaft for rotation therewith and pitch adjustment thereon; wobble mechanism between said wings axially said axis including a collar connected to the outer shaft for axial movement along said shaft and rotation therewith, an inner ring supported by said collar for tilting movement about an axis fixed with respect to saidcollar, and an outer ring journalled on the inner ring; additional wobble mechanism '5. A helicopter comprising a body; a set of wings rotatable in one direction about a drive shaft within the outer shaft for rotation therewith adjustable along ment of said wobble mechanisms, for altitudecontrol; a pair or independently pilot operable control members; means for connecting one of said control members to said wobble mechanisms for effecting simultaneous axial adjustment of said wobble mechanisms alone to efiect turning of said body; and means for connecting the other of said control members to said wobble mechanisms and to said control rod for effecting simultaneous axial adjustment of said wobble mechanisms together with said control rod to effect said altitude control.

STANLEY HILLER, JR.

v Number Name Date 1,272,846 Perry July 16, 1918 1,454,944 Pescara May 15, 1923 1,800,470 Oemichen Apr. 14, 1931 1,836,406 Smith Dec. 15, 1931 1,912,354 Pescara May 30, 1933 1,919,089 Breguet July 18, 1933 1,940,108 Sweet Dec. 19, 1933 2,041,796 Stalker May 26, 1936 2,256,918 Young Sept. 23, 1941 2,256,635 Young Sept. 23, 1941 2,321,572 Campbell June 15, 1943 2,394,846 Cox Feb. 12, 1946 FOREIGN PATENTS Number Country Date 155,985 Austria Apr. 25, 1939 REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS 

